Unitary plastic retainer ring for relatively rotatable magnetic rings



United States Patent 3,456,218 UNITARY PLASTIC RETAINER RING FOR RELA-TIVELY ROTATABLE MAGNETIC RINGS Robert Richard Melone, Des Plaines,Ill., assignor to Illinois Tool Works Inc., Chicago, Ill., a corporationof Delaware Filed Aug. 24, 1967, Ser. No. 663,101 Int. Cl. H01f N30 US.Cl. 335-212 3 Claims ABSTRACT OF THE DISCLOSURE An annular retainer tobe mounted on the neck of a television tube and includingcircumferentially spaced and oppositely extending substantially axialfinger elements to frictionally engage the neck of a television tube,and further including circumferentially spaced transversely extendinglug or shoulder means to retain therebetween relatively rotatablebeam-adjusting ring magnets which may be mounted on the retainer priorto assembly as a unit with the neck of a television tube.

The invention aims to provide an annular retainer with oppositelyextending substantially axial finger elements resiliently to engage theneck of a television tube resisting axial and rotational movementthereon and having shoulder means therearound to frictionally grip apair of ring magnets adapted for relative rotation for beamadjustingpurposes and maintain the rings in adjusted positions.

Another object of the invention is to provide a retainer substantiallyof the above type wherein certain of the axially extending fingers areelongate to project in opposite directions and arranged in assembledposition to resiliently and frictionally engage the neck of a televisiontube.

A further object of the invention is to provide a retainer substantiallyof the above type wherein certain of the axially extending fingerelements include transverse shoulder means cooperating with additionalshoulder means to retain ring magnets therebetween for relativerotation.

The invention still further aims to provide a retainer of the above typewhich may have the ring magnets initially assembled therewith for laterassociation as a composite unit with the neck of a television tube.

The above and other objects of the invention will in part be obvious andwill be hereinafter more fully pointed out.

In the accompanying drawing:

FIG. 1 is a fragmentary perspective view showing the retainer and thering magnets assembled with the neck of a television tube;

FIG. 2 is an end elevation of the retainer;

FIG. 3 is a sectional view taken substantially along the line 33 of FIG.2;

FIG. 4 is a sectional view, similar to FIG. 3, showing the magnet ringsmounted on the retainer and the entire assembly associated with the neckof a television tube; and

FIG. 5 is a sectional View taken substantially along the line 5-5 ofFIG. 2.

Referring to FIG. 1, there is shown a television tube and its reducedneck portion 10a on which the retainer 12 is assembled. As illustrated,the retainer 12 has assembled therewith two magnetic beam-adjustingrings 14, 15, each with finger engaging lug portions 14a, 15a,respectively, deflected from the planes of the respective rings for easeof grasping and manipulation when in certain proximate positions. Theuse of two annular permanent magnets arranged side by side is known foradjusting the electron beam for correct reproduction of the images onthe screen area. Further description is believed unnecessary as it isknown that by rotating either or both of the magnets, the resultantmagnet field transverse to the axis of the neck of the television tubemay be changed.

With reference to FIGS. 2 and 3, the retainer 12 is shown as includingan annular body or ring portion 16 having spaced around thecircumference thereof finger elements 18, each being identical. Eachfinger element 18 includes portions 18a, 18b extending substantiallyaxially of the body portion 16 and in opposite directions therefrom.Each finger portion 18b is provided with an inwardly directed offset endportion 20 which is somewhat thickened and is arcuate to resilientlyengage the neck of the television tube when assembled therewith. Eachoppositely extending finger portion 18a is arcuate and has thelongitudinal edges thereof terminating in inwardly directed wallportions 22, 22a in the form of ribs and with the ends thereof slightlybeveled or curved to snugly fit against the adjacent surface of the neckof the television tube when assembled therewith.

As more clearly shown in FIG. 5, there are additional finger elements24, each being identical, and circumferentially spaced around the bodyportion 16 of the retainer and extending in one substantially axialdirec tion thereof. As illustrated, each of these finger elements 24extends in the direction of the elongate finger elements 18b away fromthe body portion. Each finger element 24 includes a longitudinallydisposed and inwardly projecting rib 24a. The outer surface of eachfinger element 24 is tapered, as at 24b, to facilitate assembly of themagnetic rings 14, 15 thereover. This tapered portion 24b terminates atits inner edge in an outwardly directed shoulder 26 adapted to snuglyengage the surface of an adjacent magnetic ring 15 assembled therewith.The finger elements 24 are resiliently spread around the body portion 16between the finger elements 18.

The body portion 16 of the retainer also includes circumferentiallyspaced spring arms 28, each being identical. These spring arms aredisposed between adjacent finger elements 18, 24 and extend radiallyoutwardly from the body portion to spaced shoulder surfaces resilientlyengaging the surfaces of the other adjacent magnetic ring 14 assembledtherewith. Each of these radially extending spring arms 28 are ofreduced cross section adjacent the annular body portion 16 to providethe desired resiliency permitting rotation of the ring magnets undermanual manipulation while resisting movement from positions of relativeadjustment.

In assembling the retainer with the neck 10a of the television tube,assume that the ring magnets 14, 15 have been initially assembled withthe retainer. This is accomplished by passing the side-by-side ringmagnets 14, 15 axially of the retainer and along the inclined surfaces24b of the finger elements 24. This will force the finger elementsinwardly permitting the ring magnets to snap into position between thespring arms 28 and the shoulders 26. In this assembled position, thering magnet 14 will abut the shoulders 26 and the ring magnet 15 willhave its outer surface engaged by the spaced spring arms 28 thusmaintaining the assembled rings in position on the retainer. The springpressure exerted by the arms 28 against the ring magnet 15 is such as tomaintain the ring magnets in surface engagement and with the ring 14engaging the shoulders 26 of the finger elements 24. The spring pressureis such as to permit relative adjustment by relative rotation of thering magnets but to also maintain the ring magnets in any position towhich they have been adjusted. The composite assembly of the retainerand the ring magnets is then associated with the neck 10a of thetelevision tube by relative axial movement therebetween. The assembledposition of the retainer and the ring magnets, as shown in FIGS. 4 and5, is one wherein the inwardly offset portions 20 of the fingers 18 arespread slightly to the position shown in FIG. 4 in order to resilientlygrip the neck of the tube. At the same time, the rib portions 22, 22a ofthe finger elements 18 are spread slightly to the position shown in FIG.4 so that they, too, resiliently grip the surface of the neck of thetube. In this manner, the retainer and the magnets are resiliently andsecurely positioned on the neck of the tube. The gripping force of thefinger elements 18a, 18b on the tube surface is such as to fixedly mountthe retainer thereon while permitting relative rotation of the ringmagnets for adjustment purposes under the relatively lighter grippingaction of the spring fingers 28 against the adjacent ring magnet 15.

The retainer is made from a suitable heat-resistant plastic material toguard against distortion under influence of heat developed in the tube.To further guard against heat influence, it is to be noted that thecontact areas between the retainer and the neck of the tube are rathersmall. For example, the ribs 22, 22a provide narrow contact surfaces.Ribs 24a are designed to normally remain clear of the surface of thetube. However, when the retainer is applied to a tube neck having adiameter on the high tolerance side the retainer is slightly distortedand there is a tendency for finger elements 24 to move inwardly. Theribs 24a then engage the tube neck and reinforce elements 24 to ensurepositive engagement of shoulders 26 with the ring magnets. Likewise, thesurface contact between the finger portions 20 and the neck of the tubeare reduced as these finger portions are spread outwardly for resilientgripping to the position of FIG. 4. Still further, the outer surface ofthe annular body portion 16 is recessed, as at 30, exteriorly of fingerelements 18 and so provide peripherally spaced gaps for air circulationwithin the inner edges of the ring magnets. Said recesses 30 also assistin enhancing the resiliency of finger elements 18.

While illustrating one form of the invention, it is to be understoodthat changes in details of construction and arrangement of parts may bemade without departing from the scope of the invention as set forth inthe appended claims.

I claim:

1. A one piece continuous plastic retainer ring for attachment aroundthe neck of a television tube and adapted to support a pair ofrelatively rotatable magnetic beam-adjusting rings around the tube axis,and comprisremoval of the assembled rings in the opposite direction,

said finger elements having the recited shoulder means includinginwardlydirected substantially rigid rib means for engaging the neck of thetelevision tube to provide rigidity to said shoulder means to form apositive stop to prevent said axial movement of the adjacent magneticring in one direction and said space lug means providing biasing meansto resiliently maintain the assembled magnetic rings in position betweenthe said lug means and the said shoulder means to thereby insuremaintenance of adjusted relation between said rings.

2. A plastic retainer ring as claimed in claim 1, wherein certain of thefinger elements include resilient finger portions projecting to oppositesides of the body portion with the finger portions at one side of thebody portion having inwardly ofiset end portions for engagement with theneck of the television tube when assembled therewith and with the fingerportions on the opposite side of the body portion having spaced inwardlyprojecting rib means to engage the neck of the television tube whenassembled therewith.

3. A plastic retainer ring as claimed in claim 1, wherein the fingerportions, the finger elements with said shoulder means, and the lugmeans are circumferentially spaced from one another around the peripheryof the body portion, and wherein the body portion is recessed along theouter surface thereof at spaced intervals to provide air gaps plusresiliency to said finger elements.

References Cited UNITED STATES PATENTS 2,922,908 I/ 1960 Heller 31384 X3,303,443 2/1967 McCabe et a1. 335-212 X 3,332,046 7/1967 Melone 3352l23,376,450 4/1968 Franklin 335212 X ROBERT SEGAL, Primary Examiner

